The reputation of carbohydrates waxes and wanes depending on trends in nutritional science and public interpretation. Chemical facts that I learned years ago still hold. Take one carbon, two hydrogen, and one oxygen, CH2O (or seawater, ha!) and repeat in quantity n to get the empirical formula for the carbohydrate family: (CH2O)n . From there it quickly gets very interesting and very complicated. These handed molecules can form five- and six-membered rings and the rings can join together in marvelously intricate ways. Beyond mere aesthetics they form through sugars, starches, and cellulose the code, fuel, and structure of life. Here is Armando Hasudungan explaining more than what I once knew but since have much forgotten about these compounds. His channel is a gold mine for aged chemists and aspiring medical students.
Youtube Channel: Armando Hasudungan